I was uninstalling Norton av 7.? to install the version 9 when after trying to reboot, i cannot login to the server

It seems to bootup fine, but at the login screen, i enter username and password and after the splash screen of "loading personal ...", the computer just goes back to the login screen

NO ERROR is listed.

Any user name that I try does the same thing, always going back to the login screen

I have tried VGA / safe mode / safe mode w/ network and it does the samething each time.

This happens with or without the network cable plugged in.

help!